Reddened legs on Rooster

Every couple of weeks it is something new. Last night I went out to take a photo of our new Millie Tyson with his new family, and wound up taking photos of Sampson's legs. This has just popped up - don't know how long it's been like that. Probably a couple of days.

This was the first shot - look how tiny that bantam is!! No, wait, it's just Sampson... he's huge!

Anyway, that's when I thought he had cut himself - his legs are so red. (Pardon the muddy toes... it rained the other day!)

The scales lie flat, and I don't see any other irritations (the ID band flops loose), and I have searched high and low for an explanation... It's on both legs. Any suggestions? Is it just irritation from new feathers coming in?